Engine automatic stop-start controller

Abstract

A first ignition cylinder that performs ignition first is set based on an engine stop position in automatic start. Existence/nonexistence of a misfire in the first ignition cylinder is determined based on whether a difference ΔNe between engine rotation speed at a predetermined crank angle in an interval from timing immediately before the ignition to timing immediately after the ignition of the first ignition cylinder (e.g., at TDC of first ignition cylinder) and engine rotation speed at a predetermined crank angle before ignition of a second ignition cylinder (e.g., at TDC of second ignition cylinder) is equal to or smaller than a predetermined misfire determination threshold value Nef. When misfire time number of the first ignition cylinder exceeds a predetermined value, fuel supply to the first ignition cylinder is prohibited and the automatic start is started from the second ignition cylinder.

1. An engine automatic stop-start controller that automatically stops an engine when a predetermined automatic stop condition is established and then automatically starts the engine when a predetermined automatic start condition is established, the engine automatic stop-start controller comprising:
 a first ignition cylinder setting means for setting a first ignition cylinder that performs ignition first based on an engine stop position in the automatic start; and 
 a misfire determination means for determining existence or nonexistence of a misfire in the first ignition cylinder based on whether a difference between engine rotation speed at a predetermined crank angle in an interval from timing immediately before the ignition to timing immediately after the ignition of the first ignition cylinder and engine rotation speed at a predetermined crank angle before ignition of a second ignition cylinder is equal to or lower than a predetermined misfire determination threshold value. 
 
     
     
       2. The engine automatic stop-start controller as in  claim 1 , further comprising:
 an automatic start control means for prohibiting fuel supply to the first ignition cylinder and for starting the automatic start from the second ignition cylinder when misfire time number or misfire frequency of the first ignition cylinder sensed by the misfire determination means exceeds a predetermined value. 
 
     
     
       3. The engine automatic stop-start controller as in  claim 2 , wherein
 the misfire determination means counts the misfire time number or the misfire frequency at the time when each cylinder is the first ignition cylinder for each cylinder and stores the misfire time number or the misfire frequency in a memory for each cylinder. 
 
     
     
       4. An engine automatic stop-start controller that automatically stops an engine when a predetermined automatic stop condition is established and then automatically starts the engine when a predetermined automatic start condition is established, the engine automatic stop-start controller comprising:
 a first ignition cylinder setting means for setting a first ignition cylinder that performs ignition first based on an engine stop position in the automatic start; and 
 a misfire determination means for determining existence or nonexistence of a misfire in the first ignition cylinder based on whether engine rotation speed at a predetermined crank angle after the ignition of the first ignition cylinder and before ignition of a second ignition cylinder is equal to or lower than a predetermined misfire determination threshold value. 
 
     
     
       5. The engine automatic stop-start controller as in  claim 4 , further comprising:
 an automatic start control means for prohibiting fuel supply to the first ignition cylinder and for starting the automatic start from the second ignition cylinder when misfire time number or misfire frequency of the first ignition cylinder sensed by the misfire determination means exceeds a predetermined value. 
 
     
     
       6. The engine automatic stop-start controller as in  claim 5 , wherein
 the misfire determination means counts the misfire time number or the misfire frequency at the time when each cylinder is the first ignition cylinder for each cylinder and stores the misfire time number or the misfire frequency in a memory for each cylinder.